单纯性先天性心脏病NFATC1基因突变筛查

Association between nuclear factor of activated T cells 1 gene mutation and simple congenital heart disease in children

目的 探讨激活T细胞核因子1（NFATC1）基因在人类单纯性先天性心脏病患者中的突变情况.方法 应用聚合酶链反应（PCR）结合DNA测序技术,在56个单纯性先天性心脏病核心家系126例成员以及33例非先天性心脏病对照者中检测NFATC1基因IPT-NFAT区域的突变情况.结果 PCR扩增发现有58%（37/64）的患者以及74%（46/62）的患者一级亲属出现了2条电泳带,经测序证实2条带均为外显子7的扩增产物,分子量偏大的条带较正常的内含子区域的二倍重复序列（2×44 bp,4个单核苷酸多态性）多一个重复序列,成为三倍体（3×44 bp,6个单核苷酸多态性）重复序列.室间隔缺损、房间隔缺损以及主动脉瓣二叶畸形3类患者三倍体纯合子基因型频率为13.04%,而非先天性心脏病对照者及其他类型的先天性心脏病患者无三倍体纯合子基因型.并且主动脉瓣二叶畸形的患者其内含子的第3组重复序列的第17位碱基发现点突变（G→A）.结论 NFATC1基因与人类的心内膜垫、膜隔和动脉瓣的发育有关,可能是一种潜在的导致室间隔缺损、房间隔缺损、主动脉瓣二叶畸形的易感基因.

Objective To elucidate association between the mutation of nuclear factor of activated T cells 1 （ NFATC1 ） gene in IPT-NFAT region and simple congenital heart disease （CHD） in children. Method We used polymerase chain reaction （PCR） and the sequencing reaction to detect the mutations on the patients and their parents and （or） siblings. Results PCR amplification of the exon 7 region showed that 2 bands are obtained in 58% of patients with CHD and in 74% of their healthy parents and （or） siblings. Sequencing of the 2 bands revealed that both are amplicons of the exon 7 region, and that the additional band harbors an additional 44 nucleotides segment in the intronic region. The homozygous form of this allele was only present in patients with ventricular septal defect （2/24）, atrial septal defect （3/18） and bicuspid aortic valve （1/4） in which G to A transition at nucleotide 17 of the third 44 bps was found. Neither the unrelated non-CHD individuals nor the ones with other CHD showed positive presence for the homozygous form of this allele. Conclusions There is a differential amplification of a tandem repeat region in intron 7 of NFATC1 and homozygous form of this allele in patients with ventricular septal defect, atrial septal defect and bicuspid aortic valve. NFATC1 gene may be an a susceptibility marker for ventricular septal defect, atrial septal defect and bicuspid aortic valve.